CULTURED BUTTER COOKIES

Steps:

• In a large bowl, sift together flour, baking powder and salt.
• In an electric mixer fitted with the paddle attachment, beat together butter and granulated sugar until lightened in color and fluffy; beat in egg yolk until combined. With mixer running on low, add flour mixture until incorporated.
• Divide dough into two balls. On a clean surface, roll each ball into a 1 1/2-inch log. Sprinkle the demerara sugar over a sheet of parchment. Roll each log in the sugar until the outside of the dough is thoroughly covered. Cover logs tightly with plastic wrap and refrigerate at least one hour, or overnight.
• When you are ready to bake the cookies, heat oven to 325 degrees. Line two baking sheets with parchment. Use large, sharp knife to cut each log into 1/4-inch-thick rounds. Place cookies 1 inch apart on prepared baking sheets. Bake until cookie edges and bottoms are dark golden brown, about 18 minutes. Cool 5 minutes on baking sheets, then transfer to a wire rack to cool completely. Store in a tightly covered container at room temperature.